Marsupites americanus Springer, 1911

Remarks

• Collection:    Mississippi Museum of Natural Science.  Photo by Curator George Phillips.  Thanks!

• Formation:   Austin Group Equivalent, Eutaw Formation, Tombigbee Sand Member

• Location:      Lowndes County, Mississippi

General Info

Synonyms (older names and misidentifications in the literature)

• 1911 Marsupites americanus Springer

• 1935 Marsupites sp. Thom et al.

• 1956 Marsupites sp.  Keefer & Troyer

• 1995 Marsupites americanus Springer; Cobban

Stratigraphic Occurrence

• Eutaw Formation, Tombigbee Sand Member of Mississippi

• Colorado Group, Telegraph Creek Formation of Montana

• Colorado Group, Cody Shale of Wyoming

Age

• Both Marsupites americanus Springer and Uintacrinus socialis Grinnell occur in the Desmoscaphites bassleri Cobban Zone in the Western Interior of the United States, latest Santonian Stage (~84 mya).  So while their ranges overlap, the first occurrence of Marsupites americanus Springer is slightly younger than the first appearance of Uintacrinus socialis Grinnell.

Geographic Occurrence (by no means an all-inclusive list)

• Big Horn County, MT

• Fremont County, WY

• Lowndes County, MS

Remarks

         For identification and descriptions, see:

• Cobban, W. A.  1995.  Occurrences of the Free-Swimming Upper Cretaceous Crinoids Uintacrinus and Marsupites in the Western Interior of the United States.  United States Geological Survey Bulletin 2113-C, C1–C6; fig. 3.

• Milsom, C. V.; Simms, M. J.; Gale, A. S.  1994.  Phylogeny and Palaeobiology of Marsupites and Uintacrinus.  Palaeontology 37 (3), 595–607; text-fig. 1a is a figure of M. testudinarius (Schlotheim).